Stylus mounting



May 29, i923.

T. A. EDISON STYLUS MOUNTING Filed Deo. ll, 1919 reame Magi ae, 192e.

rasata? unirse stares earner ovarica" THOMAS A. EDISON, OF LLEWELLYN PARK., WEST ORANGE, NEW JERSEY, .ASSIGNOR T0 NEW JERSEY PATENT COMPANY, 0F WEST ORANGE, NEW JERSEY, A CORPORA- 'rIoN ors New Ji'aznsn'r.

s'rYLUs MOUNTING,

Application filed December 11, 1919. seriaino. 344,092.

To all whom t may concern:

Be it known that I, THOMAS A. EDISON, a citizen of the United States, and atresident of Llewellyn Park, in the town of vest Orange, county of Essex, and State of New Jersey, have invented certain new and useful Improvements vin Stylus Mountings (Case A), of which the following is a description.

My invention relates to stylus mountings and more especially to mountings for phonographic styli formed of a jewel, such as diamond or sapphire, and in which the stylus is partially enclosed in a metal holder and projects from a reduced end portion thereof.

The principal object of the invention is to provide an improved mounting of this character whereby the stylus will be firmly and rigidly held in its holder so as to efectually prevent the same yfrom being loosenedpin use.

My invention also resides in the method of reinforcing stylus mountings in order to attain the foregoing object.

More specifically described, my invention consists in applying reinforcing means to the stylus holder at its weakest point, that is, Where the jewel 0r stylus emerges or projects therefrom, such reinforcing means preferably being in the form' of a collar applied to the reduced end portionv ofv the holder just above the-projecting portion of the stylus so as t0 grip said reduced end portion under tension.

Other objects and features of my invention will be hereinafter more specifically described and claimed.

In order that my invention may be more clearly understood, attention is directed to the drawing accompanying and forming a part of this specication, and in which:

Figure l is a diagrammatic view partly in elevation and partly in section, of an electro-plating cell illustrating the preferred method of applying a reinforcing collar to a stylus mounting in accordance with my invention;

Fig. 2 is an enlarged view in elevation, partly in section. 0f a stylus mounting in a suitable support therefor, after the reinforcing collar has been electro-plated on the reduced end portion of the holder of the mounting; and

Fig. 3 is an enlarged view in side eleva tion of a' finishedkreinforced stylus mounting embodying myinvention.

Referring to the drawing, reference character l represents the cylindrical metal holder of an ordinary form of stylus mounting, and 2 a stylus formed-'0f diamond or other jewel, which is substantially enclosed in theholder and projects from one end thereof. The end portionof the holder 1 in which the stylus is embedded and from which it projects, is reduced,preferably being tapered down to the projecting end portion of the stylus-2. As' shown herein, the reduced end portion of the holderl and the projecting portion of the stylus 2 are formed into a cone portion having a common conical surface, that is, a continuous conical surface formed partly on the projecting portion of the stylus and partly on the adjacent end portion of the holder. The end of the stylus is rounded, as shown, preferably on an arc having a diameter of about .006 to ht the groove of a phonograph record. It Will be apparent that that portion of the holder l surrounding the embedded portion of the stylus 2 Will be quite thin and weak. In

some instances, the diamond splint or piece of any. -other jewel from Which the styuS is formed, is of such shape that this portion of the holder is almost paper-like in thickness. Accordingly it will be apparent that in stylus mountings of the character described, as now made, the styli are ofteniapt to become loose and drop out of their holders when subjected to continued use. ll have. discovered that this objection may be practically obviated by applying suitable reinforcing means to the reduced end portion of the hoiderupreferably in the form of a collar embracing and gripping the same under tension so that said collar will be permanently held on such reduced end portion by gripping engagement therewith.

Thile this reinforcing collar may be formed of various materials and'applied to the reduced endv portion of the holder in various ways. ll prefer to employ a collar separate or distinct from the holder and preferably of nickel, and to form the collar, in situ on the holder preferably by the electro-deposition of nickel thereon'in a suitable nickel plating cell. In applying such. a nickel collar to the holder, `I first secure the mounting in a suitable support 4 by fastening the cylindrical portion or shank of the therein, as by means of a set screw 5.

`With a coating C of a suitable insulating material, preferably a varnish comprising a solution ofy a coumarone or para coumarone resin such as disclosed in my pending application Serial No. 327,323 filed September 2f), 1919 and entitled --Protecting varnishes fory electrodes of electrolytie cells, which application has matured into Patent No. 1,364,359', dated January 4, 1921. The stylus mounting in the support 4 is then opposed as a cathode to a nickel anode 6 in the electrolyte 7 of a nickel-plating cell 8. A- current of suitable density is then passed through the cell by means of conductors 9 and 10 leading from a suitable source (not shown) and respectively connected to the anode G and the cathode consisting of the stylus mounting and its support. A ring or collar 11 of nickel will thus be formed in situ on'the reduced end portion 3 of the holder by being electro-plated thereon. While the stylus 2 is a non-conductor, the nickel deposited on the reduced end portion 3 of the holder 1 will, in the continued operation of the cell, build up on itself so as to cover a large part of the projecting end portion of the stylus, as shown in Fig. 2. After a ring or collar of the desired thickness has been plated on the reduced end portion of the holder 1, the stylus mounting is relnoved from the support 4, and the collar is ground down to conform to the cylindrical body portion of the holder 1. The lower por tion of this collar 11 is then ground to the shape shown in Fig. 3, and the surplus metal vat the end of the collar is removed by a suitable abrasive so as to bare that portion of the stylus 2 which projects from the holder 1. l

It is well knownthat nickel' is electro-de- -4 posited vunder great tension. Accordingly the reinforcing collar formed as described herein will grip the reduced endportion 3 of the holder luider great tension so as to be permanently held thereon, and the pressure exerted thereby will hold the stylus so irmly in the holder that the 4stylus'will break by side thrust or pressure beforel it will loosen in the holder.

While I have described the preferred form of reinforced 'stylus mounting in accordance with`my invention, and the preferred method of applying the reinforcing means theretoz it is to be understood that the same are subject to manycha-nges and modifications Without departure from the spirit of the invention and the scope of the appended claims. Having now fully described my invention, what I claim as new and desire to protect byLetters Patent, is as follows:

1. A stylus mounting comprising a holder, a stylus partially embedded in said hold.- er and extending therefrom, and a collar distinct from said holder, embracing the vportion of the holder in' which the stylus is embedded and formed in situ thereon, substantially as described.V l,

2. A stylus mounting comprising a holder having a reduced end portion, a stylus partially embedded in'said-holder and extending from the end of said portion, and a reinforcing collar electro-plated on said end portion, substantially asilescribed.

3. A stylus mounting comprising a holder having a reduced end portion, a stylus partially embedded in said holder and extending from the end of said portion, and a reinforcing collar of nickel electro-plated on sain end portion, substantially as described.

4. A stylus mounting comprising a holder having a conical end portion, a. stylus partially embedded in said holder and extending from the end of said portion, and a collar distinct from said holder embracing said conical end portion and formedin situ thereon, substantially as described.

5. A stylus mounting comprising a holder, a. stylus partially enclosed in the holder and projecting from one end thereof, the projecting endvportion of the stylus and the adjacent end portion iof the-*holder being formed into a tapered portion having a conv i tinuous taper formed partly on the holder and partly on the stylus, and a reinforcing collar embracing the tapered end portion of the holder and formed in situ fthereon, the project-ing end portion of the stylus extending below said collar, substantially as described.

6. The 'method of reinforcing a stylus -mounting comprising a holder and a stylus partially enclosed in the holder and lpro--` ecting therefrom, which consists in forming 1n situ on the portion of the holder in which the stylus 1s enclosed a reinforcing Acollar ldistinct fromithe holder, substantially' as described.

7. T he method of. reinforcing a stylus mounting comprising a holder having areduced end portion and a stylus partially enclosed in the holder: and projecting from the end of sai portion, which consists in electro-plating a collar on the reduced end portion of the holder, substantially as described. p

. 8. The method of reinforcing a stylus mounting comprising a holder having a reduced end portion and a stylus partially enclosed in the holder and projecting from the end of said portion, which consists in electroplating a nickel collar 4on thereduced end portion of the holder, and removing the surplus metal of said collar by an abrasive. substantially as described. v

9. The method of reinforcing a stylus roo mounting comprising a holder having a reduced end portion and a stylus partially enclosed in the holderand projecting from the end of said portion, which consists in placing the stylus mounting in a support, covering the exposedsurfaces of the support and stylus mounting with the exception of the reduced'end portion of said holder and the stylus With insulating material, subjecting the support with the stylus mounting therein to the action of 'an electro-plating bath Whereb)7 a collar Will be electro-plated on the reduced end portion of said holder, and removing the surplus metal from said collar and stylus so that the stylus Will project from said collar, substantially as described.

' embedded, substantially as described.

11. The method of reinforcing a stylus mounting comprising a holder having a stylus partially enclosed in the holder and projecting therefrom, which consists in electro-plating a collar on the portion of the holder in which the stylus is enclosed, substantially as described..

This specification signed and witnessed this 9th day of December 1919.

THOS. A. EDISON. 

